A simple transmitter for the 144 MHz band. Scheme, description

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A simple transmitter for the 144 MHz band. Encyclopedia of radio electronics and electrical engineering

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Encyclopedia of radio electronics and electrical engineering / Civil radio communications

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A simple two-transistor transmitter (see figure) is designed to operate in the 144 MHz band. It can be used as an exciter in more powerful transmitters or as a generator when setting up a radio receiver.

Simple transmitter on the 144 MHz band

In the master oscillator (on transistor T1), a quartz resonator with a natural resonance frequency of 48 MHz is used. The L1C2 circuit is tuned to the same frequency. Transistor T2 has a frequency tripler.

Coil L1 is wound on a frame with a diameter of 12,7 mm. It contains 8 turns of wire with a diameter of 0.25 mm. Winding length 12,7 mm. The outlet is made from the middle of the coil. Coil L2 contains 8 turns of wire with a diameter of 1,3 mm. Winding length 25 mm (frame diameter approx. 8 mm). Coil L3 contains 3 turns of wire with a diameter of 1,3 mm.

The inductance of both chokes (Dr1, Dr2) is about 1.8-2 μH.

The transmitter can use transistors KT315D and KT603A, but it is necessary to change the polarity of the power supply.

Literature

"73 Magazine" (USA), #02 1974

Publication: N. Bolshakov, rf.atnn.ru

See other articles Section Civil radio communications.

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